Internal combustion engine



Filed Feb. 28, 1936 E. mm 0 W5 m m m w i m a W 0 a a a J NM.

ATTORNEY.

Patented Aug. 24, 1937' ATENT OFFICE Ciaims.

This invention relates to improvements in internal combustion engines and has more particular reference to the variable supply of fuel for low speed and low power and forhigher 5 speed and higher power.

An important object of the invention is in the provision of means for supplying a combustible mixture to one or more passages.

A further object of the invention is to utilize the engine piston to control the passages or port openings depending upon the operation of a throttle valve.

A still further object of the invention is to simplify the structure of an engine for multiple stage control by obviating all unnecessary parts and by utilizing the piston as a fuel admission controller.

Still another object of the invention is to vary the timing of fuel admission for the proportion of the engine cycle, depending upon the speed and power desired.

In the attainment of these objects the volumetric efficiency of an internal combustion engine is improved for all speeds.

In the accompanying drawing illustrating a preferred embodiment of the invention,

Fig. 1 is a sectional view of a two-cycle crank ment of the throttle valve uncovers additional 4O manifold passages from. the mixing chamber to the compression chamber which are also controlled in various or diiferent timed relation by the piston operating in the cylinder for supplying the fuel mixture to the compression cham= ber.

Referring now more particularly to the drawing, an engine of the two-cycle type is shown having a crankcase 5 in which is an engine crank 6 having upper and lower shaftportions 50 l and 8 mounted in bearings 9 and iii respectively.

Attached to the crank case is an engine cylinder ii having a cooling water jacket i2, a fuel inlet port i3, and an opposite exhaust port it.

55 Movable in the cylinder is a piston it connected (Cl. 2.25 e-43) to the engine crank by a piston rod It. At the explosion end of the cylinder is a spark plug i'l.

Communicating with the fuel inlet port I3 is a passage l8 leading to the crank case and communicating with the discharge port I is an ex haust pipe or fitting is for the exhaust gases. In the ordinary operation of the engine fuel passes from a crank case chamber 20 through the passage l8 and from the port l3 when it is uncovered by the piston l5 at the inner or crank case end of its stroke, which also uncovers the discharge port It, allowing the escape of burnt gases, and the inlet of fresh fuel also helping to eject the burnt gases from the explosion chamber at the end of the cylinder.

The present invention relates more particularly to the supply of fuel or an explosive mixture to the crank case chamber 20 through ports 2! and 22 in the wall of the cylinder which are located to be uncovered in diiferent timed relation with respect to the engine cycle by the inner or lower edge of the piston l5 as it reciprocates in the cylinder, thereby avoiding the necessity of any extra valves or parts.

Communicating with the ports 2i and 22 is a boss 23 forming an internal chamber 24 and having a circular reduced extremity 25. A partition 26 between the openings 2| and 22 forms an abutment for one end of a sleeve 2i which fits closely in the circular extremity 25 but has a flattened side 28 to divide this inlet into two passages 29 and 30. The other end of the sleeve has an angular cut end 3! but the extremity abuts the partition 26 so that the smaller passage 29 communicates with one of the ports 2i and the larger passage 30 through the sleeve communicates with the other port 22.

Attached to the reduced extremity 25 is a carburetor or fuel admission fitting 33 which has an air inlet 34, a mixing chamber 35, a fuel inlet jet or nozzle 36 extending into the mixing chamber 35, and a throttle valve 31 rotatable or movable in the mixing chamber or in a limited arc thereof against a stop 38. At theside of this fitting which is connected to the ex tremity 25 is a partition 39 which registers with the end of the sleeve 21 and divides this portion of the passage from the mixing chamber into passages forming extensions of the passages 29 and 30.

When the throttle valve is moved against the stop 38 only the smaller passage 29 is open from the mixing chamber 35 to its corresponding port opening 2i in the cylinder (as indicated by the dotted line position of the valve 31 in Figure 2) and when the throttle valve is opened further as shown in the full lines in Fig. 2, the passage 30 is also opened for a fuel mixture from the mixing chamber 35 through the port 22.

5 By spacing the inner or leading edges of the ports 2| and 22 at various distances along the axis of the cylinder in which they are located it is obvious that they will be uncovered by the lower edge of the piston at different times in relation in to the engine cycle and will admit fuel through the cylinder and thence to the communicating crank case compression chamber 20 sooner or later and for a longer or less period, depending upon their position and size. As herein shown the lower or leading edge oi! the port 22 is uncovered by the lower edge of the piston before the corresponding edge of the port 2! which permits a larger amount of fuel to be admitted through the cylinder wall for a longer time interval than the smaller opening 2|. While only two openings and corresponding passages are provided it is obvious that additional multiple openings may be provided for further regulation if desired. By utilizing the piston skirt as the admis- 25 sion valve many additional parts are obviated and the carburetor and manifold structure is simple, efiicient, of light weight, and inexpensive.

After the explosive mixture is admitted to the crank case chamber through the ports 2| and 22 it is compressed by the piston and is used in a well known manner as heretofore explained, by the engine.

The adjustment of the carburetor or throttle valve automatically varies the amount of fuel which is admitted and the timing of its admission in accordance withthe engine cycle.

I claim: 1. In an internal combustion engine, in combination, a cylinder, 9. piston therein, a crank case open to one side of said piston, said crank case having communication, controlled by said piston, with the explosion side of said piston, said engine having a plurality of parallel passageways I for supplying combustible mixture to said cylinder on the crank case side of said piston, the ports of communication between said passageways and said cylinder being positioned to be controlled simultaneously by movement of said piston throughout at least a portion of the stroke of said 60 piston, one of said ports being adapted to admit explosive mixture throughout a difierent range of travel of said piston from another port of communication. at

2. In an internal combustion engine, in combi- 55 nation, a cylinder, a piston therein, a crank case open to one side of said piston, said crank case having communication, controlled by said piston,

with the explosion side of said piston, said engine having a plurality of parallel passageways for supplying combustible mixture to said cylinder on the crank case side 01' said piston, the ports of communication between said passageways and said cylinder being positioned to be controlled simultaneously by movement of said piston throughout at least a portion of the stroke 01' said piston, one of said ports being adapted to admit explosive mixture throughout a longer range 0! travel of said piston than another port of communication.

3. In an internal combustion engine, in combination, a cylinder, a piston therein, .a crank case open to one side of said piston, said crank case having communication, controlled by said piston, with the explosion side of said piston, said engine having a plurality of parallel passageways for supplying combustible mixture to said cylinder on the crank case side of said piston, the ports of communication between said passageways and said cylinder being positioned to be controlled simultaneously by movement of said piston, and valve means for selectably determining communication with a source of combustible mixture of one or more of said passageways, one of said ports being adapted to be uncovered by said piston at a position less distant from said crank case than is the other of said ports.

4. In a two-cycle internal combustion engine, a cylinder having a plurality of ports adapted to communicate with the crank case of said engine on the crank case side of the piston of said engine, said ports being positioned to be controlled by said piston to admit a combustible mixture into said crank case, a portion of one of said ports being positioned to open later than another of said ports as said piston travels away from the crank case end of said cylinder, said ports being disposed circumferentially about said cylinder.

5. In an internal combustion engine, in combination, a cylinder, a piston therein, said engine having means for supplying a combustible mixture to said cylinder on the crank case side of said piston, said means including a plurality of passages, and valve means for controlling progressively the supply 01' combustible mixture to said passages, said cylinder having ports communicating with said passages, said ports being distributed circumferentially of said cylinder and disposed in position to be simultaneously controlled by said piston, one of said ports being adapted to admit explosive mixture throughout a diiferent range of travel of said piston from another of said ports.

CLARENCE L. JOHNSON. 

